Visualization Analysis & Design Full-Day Tutorial Session 3 Tamara Munzner Department of Computer Science University of British Columbia Sanger Institute / European Bioinformatics Institute June 2014, Cambridge UK http://www.cs.ubc.ca/~tmm/talks.html#minicours e14 Outline • Visualization Analysis Framework Session 1 9:30-10:45am – Introduction: Definitions – Analysis: What, Why, How – Marks and Channels • Idiom Design Choices, Part 2 Session 3 1:15pm-2:45pm – Manipulate: Change, Select, Navigate – Facet: Juxtapose, Partition, Superimpose – Reduce: Filter, Aggregate, Embed • Idiom Design Choices Session 2 11:00am-12:15pm – Arrange Tables http://www.cs.ubc.ca/~tmm/talks.html#minicourse14 2 Idiom design choices: Part 1 3 Idiom design choices: Part 2 4 Manipulate 5 Change over time • change any of the other choices – encoding itself – parameters – arrange: rearrange, reorder – aggregation level, what is filtered... • why change? – one of four major strategies • change over time • facet data by partitioning into multiple views • reduce amount of data shown within view – embedding focus + context together – most obvious, powerful, flexible – interaction entails change 6 Idiom: Re-encode System: Tableau made using Tableau, http://tableausoftware.com 7 Idiom: Reorder System: LineUp • data: tables with many attributes • task: compare rankings [LineUp: Visual Analysis of Multi-Attribute Rankings. Gratzl, Lex, Gehlenborg, Pfister, and Streit. IEEE Trans. Visualization and Computer Graphics (Proc. InfoVis 2013) 19:12 (2013), 2277–2286.] 8 System: LineUp Idiom: Realign • stacked bars – easy to compare • first segment • total bar • align to different segment – supports flexible comparison [LineUp: Visual Analysis of Multi-Attribute Rankings.Gratzl, Lex, Gehlenborg, Pfister, and Streit. IEEE Trans. Visualization and Computer Graphics (Proc. InfoVis 2013) 19:12 (2013), 2277–2286.] 9 Idiom: Animated transitions • smooth transition from one state to another – alternative to jump cuts – support for item tracking when amount of change is limited • example: multilevel matrix views – scope of what is shown narrows down • middle block stretches to fill space, additional structure appears within • other blocks squish down to increasingly aggregated representations [Using Multilevel Call Matrices in Large Software Projects. van Ham. Proc. IEEE Symp. Information Visualization (InfoVis), pp. 227– 232, 2003.] 10 Select and highlight • selection: basic operation for most interaction • design choices – how many selection types? • click vs hover: heavyweight, lightweight • primary vs secondary: semantics (eg source/target) • highlight: change visual encoding for selection targets – color • limitation: existing color coding hidden – other channels (eg motion) – add explicit connection marks between items 11 Navigate: Changing item visibility • change viewpoint – changes which items are visible within view – camera metaphor • zoom – geometric zoom: familiar semantics – semantic zoom: adapt object representation based on available pixels » dramatic change, or more subtle one • pan/translate • rotate – especially in 3D – constrained navigation • often with animated transitions • often based on selection set 12 Idiom: Semantic zooming System: LiveRAC • visual encoding change – colored box – sparkline – simple line chart – full chart: axes and tickmarks [LiveRAC - Interactive Visual Exploration of System Management Time-Series Data. McLachlan, Munzner, Koutsofios, and North. Proc. ACM Conf. Human Factors in Computing Systems (CHI), pp. 1483–1492, 2008.] 13 Navigate: Reducing attributes • continuation of camera metaphor – slice • show only items matching specific value for given attribute: slicing plane • axis aligned, or arbitrary alignment – cut • show only items on far slide of plane from camera – project • change mathematics of image creation – orthographic [Interactive–Visualization of Multimodal Volume Data for Neurosurgical Tumor Treatment. Rieder, Ritter, Raspe, and Peitgen. perspective Computer Graphics Forum (Proc. EuroVis 2008) 27:3 (2008), 1055–1062.] 14 Further reading • Visualization Analysis and Design. Munzner. AK Peters / CRC Press, Oct 2014. – Chap 11: Manipulate View • Animated Transitions in Statistical Data Graphics. Heer and Robertson. IEEE Trans. on Visualization and Computer Graphics (Proc. InfoVis07) 13:6 (2007), 1240– 1247. • Selection: 524,288 Ways to Say “This is Interesting”. Wills. Proc. IEEE Symp. Information Visualization (InfoVis), pp. 54–61, 1996. • Smooth and efficient zooming and panning. van Wijk and Nuij. Proc. IEEE Symp. Information Visualization (InfoVis), pp. 15–22, 2003. • Starting Simple - adding value to static visualisation through simple interaction. Dix and Ellis. Proc. Advanced Visual Interfaces (AVI), pp. 124–134, 1998. 15 Outline • Visualization Analysis Framework Session 1 9:30-10:45am – Introduction: Definitions – Analysis: What, Why, How – Marks and Channels • Idiom Design Choices, Part 2 Session 3 1:15pm-2:45pm – Manipulate: Change, Select, Navigate – Facet: Juxtapose, Partition, Superimpose – Reduce: Filter, Aggregate, Embed • Idiom Design Choices Session 2 11:00am-12:15pm – Arrange Tables http://www.cs.ubc.ca/~tmm/talks.html#minicourse14 16 Facet 17 Juxtapose and coordinate views 19 Idiom: Linked highlighting System: EDV • see how regions contiguous in one view are distributed within another – powerful and pervasive interaction idiom • encoding: different – multiform • data: all shared [Visual Exploration of Large Structured Datasets. Wills. Proc. New Techniques and Trends in Statistics (NTTS), pp. 237–246. IOS Press, 1995.] 20 Idiom: bird’s-eye maps System: Google Maps • encoding: same • data: subset shared • navigation: shared – bidirectional linking • differences – viewpoint – (size) • overview-detail [A Review of Overview+Detail, Zooming, and Focus+Context Interfaces. Cockburn, Karlson, and Bederson. ACM Computing Surveys 41:1 (2008), 1–31.] 21 Idiom: Small multiples • encoding: same • data: none shared System: Cerebral – different attributes for node colors – (same network layout) • navigation: shared [Cerebral: Visualizing Multiple Experimental Conditions on a Graph with Biological Context. Barsky, Munzner, Gardy, and 22 Kincaid. IEEE Trans. Visualization and Computer Graphics (Proc. InfoVis 2008) 14:6 (2008), 1253–1260.] Coordinate views: Design choice interaction 23 Juxtapose design choices • design choices – view count • few vs many – how many is too many? open research question – view visibility • always side by side vs temporary popups – view arrangement • user managed vs system arranges/aligns • why juxtapose views? – benefits: eyes vs memory • lower cognitive load to move eyes between 2 views than remembering previous state with 1 – costs: display area 24 System: Improvise • investigate power of multiple views – pushing limits on view count, interaction complexity – reorderable lists • easy lookup • useful when linked to other encodings [Building Highly-Coordinated Visualizations In Improvise. Weaver. Proc. IEEE Symp. Information Visualization (InfoVis), pp. 159–166, 2004.] 25 Partition into views • how to divide data between views – encodes association between items using spatial proximity – major implications for what patterns are visible – split according to attributes • design choices – how many splits • all the way down: one mark per region? • stop earlier, for more complex structure within region? 26 Views and glyphs • view – contiguous region in which visually encoded data is shown on the display • glyph – object with internal structure that arises from multiple marks • no strict dividing line – view: big/detailed – glyph:small/iconic 27 Partitioning: List alignment • single bar chart with grouped bars – split by state into regions • complex glyph within each region showing all ages – compare: easy within state, hard across ages • small-multiple bar charts – split by age into regions • one chart per region – compare: easy within age, harder across states 28 Partitioning: Recursive subdivision System: HIVE • split by type • then by neighborhood • then time – years as rows – months as columns [Configuring Hierarchical Layouts to Address Research Questions. Slingsby, Dykes, and Wood. IEEE Transactions on Visualization 29 and Computer Graphics (Proc. InfoVis 2009) 15:6 (2009), 977–984.] Partitioning: Recursive subdivision System: HIVE • switch order of splits – neighborhood then type • very different patterns [Configuring Hierarchical Layouts to Address Research Questions. Slingsby, Dykes, and Wood. IEEE Transactions on Visualization 30 and Computer Graphics (Proc. InfoVis 2009) 15:6 (2009), 977–984.] Partitioning: Recursive subdivision System: HIVE • size regions by sale counts – not uniformly • result: treemap [Configuring Hierarchical Layouts to Address Research Questions. Slingsby, Dykes, and Wood. IEEE Transactions on Visualization 31 and Computer Graphics (Proc. InfoVis 2009) 15:6 (2009), 977–984.] Partitioning: Recursive subdivision System: HIVE • different encoding for second-level regions – choropleth maps [Configuring Hierarchical Layouts to Address Research Questions. Slingsby, Dykes, and Wood. IEEE Transactions on Visualization 32 and Computer Graphics (Proc. InfoVis 2009) 15:6 (2009), 977–984.] Superimpose layers • layer: set of objects spread out over region – each set is visually distinguishable group – extent: whole view • design choices – how many layers? – how are layers distinguished? – small static set or dynamic from many possible? – how partitioned? • heavyweight with attribs vs lightweight with selection • distinguishable layers – encode with different, nonoverlapping channels • two layers achieveable, three with careful design 33 Static visual layering • foreground layer: roads – hue, size distinguishing main from minor – high luminance contrast from background • background layer: regions – desaturated colors for water, parks, land areas • user can selectively focus attention • “get it right in black and white” – check luminance contrast with greyscale view [Get it right in black and white. Stone. 2010. http://www.stonesc.com/wordpress/2010/03/get-it-right-in-blackand-white] 34 Superimposing limits • few layers, but many lines – up to a few dozen – but not hundreds • superimpose vs juxtapose: empirical study – superimposed for local visual, multiple for global – same screen space for all multiples, single superimposed – tasks • local: maximum, global: slope, discrimination [Graphical Perception of Multiple Time Series. Javed, McDonnel, and Elmqvist. IEEE Transactions on Visualization and Computer Graphics (Proc. IEEE InfoVis 2010) 16:6 (2010), 927–934.] 35 Dynamic visual layering • interactive, from selection System: Cerebral – lightweight: click – very lightweight: hover • ex: 1-hop neighbors [Cerebral: a Cytoscape plugin for layout of and interaction with biological networks using subcellular localization annotation. Barsky, Gardy, Hancock, and Munzner. Bioinformatics 36 Further reading • Visualization Analysis and Design. Munzner. AK Peters / CRC Press, Oct 2014. – Chap 12: Facet Into Multiple Views • A Review of Overview+Detail, Zooming, and Focus+Context Interfaces. Cockburn, Karlson, and Bederson. ACM Computing Surveys 41:1 (2008), 1–31. • A Guide to Visual Multi-Level Interface Design From Synthesis of Empirical Study Evidence. Lam and Munzner. Synthesis Lectures on Visualization Series, Morgan Claypool, 2010. • Zooming versus multiple window interfaces: Cognitive costs of visual comparisons. Plumlee and Ware. ACM Trans. on Computer-Human Interaction (ToCHI) 13:2 (2006), 179–209. • Exploring the Design Space of Composite Visualization. Javed and Elmqvist. Proc. Pacific Visualization Symp. (PacificVis), pp. 1–9, 2012. • Visual Comparison for Information Visualization. Gleicher, Albers, Walker, Jusufi, Hansen, and Roberts. Information Visualization 10:4 (2011), 289–309. • Guidelines for Using Multiple Views in Information Visualizations. Baldonado, Woodruff, and Kuchinsky. In Proc. ACM Advanced Visual Interfaces (AVI), pp. 110–119, 2000. • Cross-Filtered Views for Multidimensional Visual Analysis. Weaver. IEEE Trans. Visualization and Computer Graphics 16:2 (Proc. InfoVis 2010), 192–204, 2010. • Linked Data Views. Wills. In Handbook of Data Visualization, Computational Statistics, edited by Unwin, Chen, and Härdle, pp. 216–241. Springer-Verlag, 2008. • Glyph-based Visualization: Foundations, Design Guidelines, Techniques and Applications. Borgo, Kehrer, Chung, Maguire, Laramee, Hauser, Ward, and Chen. In Eurographics State of the Art Reports, pp. 39–63, 2013. 37 Outline • Visualization Analysis Framework Session 1 9:30-10:45am – Introduction: Definitions – Analysis: What, Why, How – Marks and Channels • Idiom Design Choices, Part 2 Session 3 1:15pm-2:45pm – Manipulate: Change, Select, Navigate – Facet: Juxtapose, Partition, Superimpose – Reduce: Filter, Aggregate, Embed • Idiom Design Choices Session 2 11:00am-12:15pm – Arrange Tables http://www.cs.ubc.ca/~tmm/talks.html#minicourse14 38 Reduce items and attributes • reduce/increase: inverses • filter – pro: straightforward and intuitive • to understand and compute – con: out of sight, out of mind • aggregation – pro: inform about whole set – con: difficult to avoid losing signal • not mutually exclusive – combine filter, aggregate – combine reduce, change, facet 39 Idiom: dynamic filtering System: FilmFinder • item filtering • browse through tightly coupled interaction – alternative to queries that might return far too many or too few [Visual information seeking: Tight coupling of dynamic query filters with starfield displays. Ahlberg and Shneiderman. Proc. ACM Conf. on Human Factors in Computing Systems (CHI), pp. 313–317, 1994.] 40 Idiom: scented widgets • augment widgets for filtering to show information scent – cues to show whether value in drilling down further vs looking elsewhere • concise, in part of screen normally considered control panel [Scented Widgets: Improving Navigation Cues with Embedded Visualizations. Willett, Heer, and Agrawala. IEEE Trans. Visualization and Computer Graphics (Proc. InfoVis 2007) 13:6 (2007), 1129– 1136.] 41 Idiom: DOSFA • attribute filtering • encoding: star glyphs [Interactive Hierarchical Dimension Ordering, Spacing and Filtering for Exploration Of High Dimensional Datasets. Yang, Peng,Ward, and. Rundensteiner. Proc. IEEE Symp. Information Visualization (InfoVis), pp. 105–112, 2003.] 42 Idiom: histogram • • • • static item aggregation task: find distribution data: table derived data – new table: keys are bins, values are counts • bin size crucial – pattern can change dramatically depending on discretization – opportunity for interaction: control bin size on the fly 43 Idiom: boxplot • • • • static item aggregation task: find distribution data: table derived data – 5 quant attribs • median: central line • lower and upper quartile: boxes • lower upper fences: whiskers – values beyond which items are outliers – outliers beyond fence cutoffs explicitly shown [40 years of boxplots. Wickham and Stryjewski. 2012. had.co.nz] 44 Idiom: Hierarchical parallel coordinates • dynamic item aggregation • derived data: hierarchical clustering • encoding: – cluster band with variable transparency, line at mean, width by min/max values – color by proximity in hierarchy [Hierarchical Parallel Coordinates for Exploration of Large Datasets. Fua, Ward, and Rundensteiner. Proc. IEEE Visualization Conference (Vis ’99), pp. 43– 50, 1999.] 45 Dimensionality reduction • attribute aggregation – derive low-dimensional target space from high-dimensional measured space – use when you can’t directly measure what you care about • true dimensionality of dataset conjectured to be smaller than dimensionality of measurements • latent factors, hidden variables Malignant Benign Tumor Measurement Data DR data: 9D measured space derived data: 2D target space 46 46 Dimensionality reduction for documents 47 Embed: Focus+Context • combine information within single view • elide – selectively filter and aggregate • superimpose layer – local lens • distortion design choices – region shape: radial, rectilinear, complex – how many regions: one, many 49 Idiom: DOITrees Revisited • elide – some items dynamically filtered out – some items dynamically aggregated together – some items shown in detail 50 [DOITrees Revisited: Scalable, Space-Constrained Visualization of Hierarchical Data. Heer and Card. Proc. Advanced Visual Interfaces (AVI) Idiom: Fisheye Lens • distort geometry – shape: radial – focus: single extent – extent: local – metaphor: draggable lens http://tulip.labri.fr/TulipDrupal/?q=node/351 http://tulip.labri.fr/TulipDrupal/?q=node/371 51 Idiom: Stretch and Squish Navigation • distort geometry – shape: rectilinear System: – foci: multiple – impact: global – metaphor: stretch and squish, borders fixed TreeJuxtaposer [TreeJuxtaposer: Scalable Tree Comparison Using Focus+Context With Guaranteed Visibility. Munzner, Guimbretiere, Tasiran, Zhang, and Zhou. ACM Transactions on Graphics (Proc. SIGGRAPH) 22:3 (2003), 453– 462.] 52 Distortion costs and benefits fisheye lens magnifying lens neighborhood layering Bring and Go • benefits – combine focus and context information in single view • costs – length comparisons impaired • network/tree topology comparisons unaffected: connection, containment – effects of distortion unclear if original structure unfamiliar – object constancy/tracking maybe impaired [Living Flows: Enhanced Exploration of Edge-Bundled Graphs Based on GPU-Intensive Edge Rendering. Lambert, Auber, and Melançon. Proc. Intl. Conf. Information Visualisation (IV), pp. 523–530, 2010.] 53 Further reading • Visualization Analysis and Design. Munzner. AK Peters / CRC Press, Oct 2014. – Chap 14: Embed: Focus+Context • A Review of Overview+Detail, Zooming, and Focus+Context Interfaces. Cockburn, Karlson, and Bederson. ACM Computing Surveys 41:1 (2008), 1–31. • A Guide to Visual Multi-Level Interface Design From Synthesis of Empirical Study Evidence. Lam and Munzner. Synthesis Lectures on Visualization Series, Morgan Claypool, 2010. • Hierarchical Aggregation for Information Visualization: Overview, Techniques and Design Guidelines. Elmqvist and Fekete. IEEE Transactions on Visualization and Computer Graphics 16:3 (2010), 439–454. 54